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Finding the Fourth Proportional to 721.85, 1,080.68 and 538.79

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Solution

The fourth proportional to 721.85, 1,080.68 and 538.79 is: 806.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.85 : 1,080.68 = 538.79 : x
  2. Step 2: Convert to fraction form
    721.85/1,080.68 = 538.79/x
  3. Step 3: Cross multiply
    721.85x = 1,080.68 × 538.79
  4. Step 4: Simplify right side
    721.85x = 582,251.48
  5. Step 5: Solve for x
    x = 582,251.48/721.85
  6. Step 6: Final answer
    x = 806.62

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.